Shape memory behavior of emulsion-templated poly( [epsilon] -caprolactone) synthesized by organocatalyzed ring-opening polymerization
| Autor: | Ema Žagar, Petra Utroša, Sebastijan Kovačič, David Pahovnik, Ozgun Can Onder |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
udc:54 Polymers and Plastics Organic Chemistry kemija kristalizacija Shape-memory alloy termomehanske lastnosti Ring-opening polymerization law.invention polimerizacija Inorganic Chemistry Crystallinity chemistry.chemical_compound Chemical engineering chemistry Polymerization law Emulsion Materials Chemistry Crystallization Porosity Caprolactone |
| Zdroj: | Macromolecules, vol. 52, no. 23, pp. 9291-9298, 2019. |
| ISSN: | 0024-9297 |
| Popis: | Organocatalyzed ring-opening polymerization (ROP) of e-caprolactone (CL) and 4,4′-bioxepanyl-7,7′-dione as a bis-lactone cross-linker was performed within the oil-in-oil high internal phase emulsions (HIPEs) at 50 °C. In this way, the cross-linked poly(e-caprolactone) (PCL) polyHIPE foams of ∼85% porosity were synthesized. Thermomechanical properties of the prepared polyHIPEs were studied and proved to greatly depend on a degree of PCL cross-linking. The melting and crystallization temperatures as well as the degree of crystallinity of PCL polyHIPE foams decrease with an increasing cross-linking degree. Semi-crystalline polyHIPEs demonstrate shape memory behavior with excellent shape fixity and shape recovery. At an appropriate degree of PCL cross-linking, the polyHIPE temporary shape can be fixed at room temperature, while a transition to the permanent shape occurs upon heating at 40 °C. Moreover, a two-way shape memory behavior of the PCL polyHIPEs under constant stress was observed. |
| Databáze: | OpenAIRE |
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